Automatic releasing device for a parachute

ABSTRACT

A device for the automatic opening of a parachute, comprising a casing ( 1 ) closed with a lid ( 2 ), in which are located the means ( 3, 14 ) for electronically sensing the altitude of the parachute during the jump and the lime and falling speed, and their controlling elements with a display unit and joint power supply, further comprising an activating unit consisting of an electrically controlled cutting explosive cartridge ( 12 ) with a through opening through which a ripcord ( 3 ) passes to release the securing string of the parachute, this explosive cartridge ( 12 ) being joined to said means by a connecting cable. The cutting explosive cartridge ( 12 ) is positioned in the interior space of the casing ( 1 ) formed by its partitions ( 4 ) and its connecting cable is led through the partition, while the casing ( 1 ), which together with the lid ( 2 ) consists of a body made of shock resistant material, is arranged for securing in the back part of the parachute harness.

FIELD OF THE INVENTION

The invention concerns an automatic releasing device for a main orreserve parachute which is based on the principle of electronic sensingof the altitude of the parachute during the jump and the falling speed.

DESCRIPTION OF THE PRIOR ART

Accidental risk situations can arise during parachute jumping where theskydiver during free fall finds himself at a dangerously low altitudewithout the parachute opening. This problem was solved by the automaticopening of the main or reserve parachute. Known systems for automaticopening of the parachute are based on the principle of atmosphericpressure measurement in the course of the jump, where the altitude isdetermined by this value. To measure the pressure, older automaticparachute opening devices use mechanical membrane meters, aneroids,which are reliable. In recent times use has spread of equivalentpressure sensors on the electronic principle, for example semiconductoror piezoelectric sensors.

The processing of a signal from an aneroid was carried out by means of amechanical device and to release the reserve or main parachute a springwas used whose thrust resulted in the release of the securing string ofthe parachute container. This mechanical device was very reliable, butfairly bulky and heavy, and moreover it was susceptible to vibration andmechanical shock. With the development of electronics andmicroelectronics it was possible gradually to replace mechanical withelectronic devices which work on the same principle. The pressure ismeasured and the instant altitude and falling speed values aredetermined from the measured pressure values. The advantage of theseelectronic devices compared to the equivalent mechanical device lies intheir smaller size and weight. Moreover the electronic device permitsadditional functions for more precise determination of the correctmoment for emergency opening of the parachute.

The currently known electronic equipment consists of three basic partswhich are connected by electric cables. In the basic unit there is theelectric power supply, measuring and controlling electronic circuits asthe case may be. A further part consists of the controlling unit (with adisplay unit and push-button, and possibly a light-emitting diode andswitch) for turning the device on and off and adjusting its functions.Finally the third part is the activating unit, consisting of anelectrically controlled cutting explosive cartridge, through which thereleasing string of the parachute passes. A related disadvantage of allthe current embodiments is the existence of connecting cables whichreduce the reliability of the device and also increase the amount ofspace taken up in the parachute container. These embodiments are moredemanding in terms of installation and operating stress. The knownembodiments of the above mentioned devices, their principles and actualexecution, are described in a series of patent files, for example U.S.Pat. Nos. 2,497,772, 3,023,498, 3,142,958, 3,300,606, 3,547,383,3,813,066, 3,820,748, 4,792,903, 4,858,856, 5,024,400, European PatentsNos. 0281159, 0480733, 0838395, 0785130, 1084950 etc.

SUMMARY OF THE INVENTION

The technical solution concerns a device for the automatic opening of aparachute, comprising a casing closed with a lid, in which are locatedthe means for electronically sensing the altitude of the parachuteduring the jump and the time and falling speed, and their controllingelements with a display unit and joint power supply, further comprisingan activating unit consisting of an electrically controlled cuttingexplosive cartridge with a through opening through which a ripcordpasses to release the securing string of the parachute, this explosivecartridge being joined to said means by a connecting cable.

The basis of this technical solution lies in the fact that the cuttingexplosive cartridge is positioned in the interior space of the casingformed by its partitions and its connecting cable is led through thepartition, while the casing, which together with the lid consists of abody made of shock-resistant material, is arranged for securing in theback part of the parachute harness. The advantage is the smaller sizeand increased resistance to outside influences of the device forautomatic opening of the reserve parachute, particularly to mechanicalinfluences and also electromagnetic disturbance, and thereby an increasein its overall reliability.

The casing is preferably a flat metal box having in the central area twopartitions running from the bottom up to the lid, which divides theinside of the casing into three areas arranged side by side. In oneouter area there are located the means for electronically sensing thealtitude of the parachute during the jump and the time and fallingspeed, and their controlling elements with a display unit, in the secondouter area is the power supply, and in the area between them, in whichis positioned the cutting explosive cartridge, there is an opening inthe bottom for passage to the outside of the casing of the functionalend of the ripcord for releasing the securing string of the parachute.In the recess of the two partitions there is a plate for fastening theother end of the ripcord for releasing the securing string of theparachute, spanning the area between the partitions above the cuttingexplosive cartridge. A passage for the connecting cable is formed by anupper slot in the end area of one of the two partitions, and in theopposite end area, where the two partitions are connected in a jointreinforcement, an upper through slot joining the two outer areas forguiding the feeder cable is formed in that reinforcement.

The device is small, very compact and mechanically resistant. There areno outer connecting cables. The power supply, which is replaceable, isarranged in a section of the casing separated from the section with thefirmly installed controlling electronics. All the parts are enclosed ina solid metal (or plastic) casing, lodged in the back part of theparachute harness in a free space for the draw of the ripcord forreleasing the securing string of the parachute. No part of the device isexposed to the direct effect of the surrounding environment. The casingof the device does not protrude into or out of the parachute container,the device is smoothly integrated into the harness and container andthere is no practical possibility of negative interaction with any partof the main or reserve parachute, either during free fall, in the courseof opening the parachute or during parachute fall or gliding.

The lid secured in the recess of the casing, in the region above thearea with the means for electronically sensing the altitude of theparachute during the jump, the time and falling speed, has incisions forthe display unit and the controlling push-buttons, and in the regionabove the plate for securing the other end of the ripcord for releasingthe securing string of the parachute, it is furnished with amanipulation opening. After being inserted into the pocket in the backpart of the parachute harness in the area for the passage of the ripcordto release the securing string of the parachute, this ripcord passesthrough the device. The pocket is transparent on the side of the displayunit and of the controlling push-buttons of the device, to allow accessto these elements. The device can also replace the metal or plasticplate in the back part of the parachute harness, against which rests thespring of the extracting parachute for the reserve parachute.

BRIEF DESCRIPTION OF THE DRAWINGS

The technical solution will be further explained with a concrete exampleof one of its possible embodiments, with the help of the attacheddrawings and the description that follows.

FIG. 1 illustrates the structural arrangement of the device in partialvertical lengthwise section.

FIG. 2 shows a perspective view from above.

FIG. 3 shows a vertical transverse section in the area of the outlet forthe ripcord to release the securing string of the reserve parachute.

FIG. 4 illustrates the covering lid of the device in perspective viewand

FIG. 5 shows this covering lid in transverse section.

FIG. 6 shows the arrangement of the device, including the ripcord torelease the securing string of the reserve parachute, in perspective,lengthwise and vertical section.

EXAMPLES OF PREFERRED EMBODIMENTS

The automatic releasing device for a parachute is structurally formed asa flat metal box made of a light aluminium alloy, having in the centralarea two thick-walled partitions 4 running from the bottom 5 up to thelid 2, which divides the inside of the casing 1 of the box into threeareas or sections arranged side by side. In one outer area, the firstsection 13 of the casing 1, there is a securely installed electroniccontrol device. This comprises a single-chip controller, a circuit forcontrolling a minimum consumption of power from the power supply device(replaceable battery), an electronic pressure sensor, a real time clock,a memory and push-buttons for the keyboard and display unit. Theelectronic pressure sensor serves to measure the instant values ofatmospheric pressure in the locality and in the course of the jump.During free fall and parachute gliding, the instant atmospheric pressurevalue is mathematically converted into an instant altitude value. Fromthe time difference of the instant altitude values, the speed of thefall is automatically calculated. If this speed exceeds the limit valueunder the critical height, the release mechanism of the ripcord forreleasing the securing string of the parachute is activated and theparachute opens automatically. The real time clock serves to measure thetime intervals. It is constantly working, even if the device is switchedoff. This clock calculates the time from when the device is put intooperation and resets only during disconnection of the power supply(battery). It gives a warning on the lifespan of the battery,automatically checks the switching on and off of the device and ensuresthe periodic exact reading by the sensor of the atmospheric pressure.All the measured values are continuously recorded in the memory of thedevice, in such a way that the oldest values are always replaced. In thecase of activation, it is possible to use those values that are storedfor retrospective analysis of a situation that has arisen. The number ofactual jumps, the altitude of the jump, the altitude at which theparachute opened, the falling speed and other values are also recordedin the memory. By means of the keyboard push-buttons, it is possible tobring up all of the data onto the display unit. It is also possible toswitch the device on and off by means of the keyboard, or to change theparameters for performance of the device as the case may be.

In the second outer area, the second section 14 of the casing X, thereis the replaceable power supply for the device, the batteries. Theoutput from these batteries is conveyed by the power cable located inthe upper through slot 9 in the adjacent end area of the jointreinforcement of the two partitions 4 of the casing 1, to the electroniccontrol device in the first section 13 of the casing 1.

The cutting explosive cartridge 12 is positioned in the third section 15in the area between the two outer sections 13 and 14. This third section15 has an opening 6 in the bottom 5 for the passage of the functionalend of the release of the securing string of the parachute, in therecess of the two partitions 4 defining the width of the third sectionA, there is a plate 7 for fastening the other end of the ripcord 3 forreleasing the securing string of the parachute, spanning the areabetween the partitions 4 above the cutting explosive cartridge 12. Apassage for the connecting cable from the electronic control to thecutting explosive cartridge 12 is formed by an upper slot 8 in the endarea of the partitions 4 between the first 13 and third section 15 ofthe casing 1. The release of the securing string of the parachute can beused once only. In case of activation it must be changed for a new one.Activation is carried out electronically by means of the built-incutting explosive cartridge 12.

Secured in the recess of the casing 1 there is a lid 2 made of a lightaluminium alloy which, in the region above the first section 13 with theelectronic control, has incisions 10 for the display unit and thecontrolling push-buttons of the keyboard.

In the region above the plate 7 for securing the other end of theripcord 3 for releasing the securing string of the parachute, above thethird section 15 of the casing 1, the lid 2 has a manipulation opening11.

The casing 1 together with the lid 2 consists of a body made ofshock-resistant material. It is arranged for securing in the back partof the parachute harness. After being inserted into the pocket in theback part of the parachute harness in the area for the passage of theripcord 3 to release the securing string of the parachute, this ripcord3 passes through the device. The pocket is transparent on the side ofthe display unit and of the controlling push-buttons of the device, toallow access to these elements. The device can also replace the metal orplastic plate in the back part of the parachute harness, against whichrests the spring of the extracting parachute for the reserve parachute.

The device according to this solution is integrated into the parachuteharness and container, so that there is practically no possibility ofnegative interaction with any part of the main or reserve parachute,either during free fall, in the course of opening the parachute orduring parachute fall or gliding.

1. A device for the automatic opening of a parachute, comprising: a casing closed with a lid, in which are located the means for electronically sensing the altitude of the parachute during the jump and the time and falling speed, and their controlling elements with a display unit and joint power supply, further comprising an activating unit consisting of an electrically controlled cutting explosive cartridge with a through opening through which a ripcord passes to release the securing string of the parachute, this explosive cartridge being joined to said means by a connecting cable, wherein the cutting explosive cartridge is positioned in the interior space of the casing formed by its partitions and its connecting cable is led through the partition, while the casing, which together with the lid consists of a body made of shock-resistant material, is arranged for securing in the back part of the parachute harness.
 2. A device according to claim 1, wherein the casing is a flat metal box having in the central area two partitions running from the bottom up to the lid, which divides the inside of the casing into three areas arranged side by side, where in one outer area there are located the means for electronically sensing the altitude of the parachute during the jump and the time and falling speed, and their controlling elements with a display unit, in the second outer area is the power supply, and in the area between them, in which is positioned the cutting explosive cartridge, there is an opening in the bottom for passage to the outside of the casing of the functional end of the ripcord for releasing the securing string of the parachute, and where in the recess of the two partitions there is a plate for fastening the other end of the ripcord for releasing the securing string of the parachute, spanning the area between the partitions above the cutting explosive cartridge, where a passage for the connecting cable is formed by an upper slot in the end area of one of the two partitions, and in the opposite end area, where the two partitions are connected in a joint reinforcement, an upper through slot joining the two outer areas for guiding the feeder cable is formed in that reinforcement.
 3. A device according to claim 2, wherein the lid secured in the recess of the casing, in the region above the area with the means for electronically sensing the altitude of the parachute during the jump, the time and falling speed, has incisions for the display unit and the controlling push-buttons, and in the region above the plate for securing the other end of the ripcord for releasing the securing string of the parachute, it is furnished with a manipulation opening. 